Sanding and polishing machines



A g- 27, 957 J. A. NYLUND ETAL 2,303,927

SANDING AND POLISHING MACHINES I Filed Nov'. 15, 1956 5 Sheets-Sheet 1 INVENTORS JOHN A. NYLUND BY FRANK J. MIEHE ATTO R NEYS 27, 1957 .1. A. NYLUND ETAL 2,303,927

SANDING AND POLISHING MACHINES x 3 Sheets-Sheet 3 Filed Nov. 15. 1956 i l I IIQViENTORF JOHN A. NYLUND FRANK J. MIEHE ATTO R N EYS United States Patent 9 SANDING AND POLISHING MACHINES John A. Nylund, Portland, and Frank J. Miehe, Lake Grove, Oreg.

Application November 15, 1956, Serial No. 622,430

Claims. (Cl. 51--141) The present invention relates to sanding and polishing machines, and more particularly to belt type sanding and surfacing machines.

The primary object of the invention is to provide a sanding and polishing machine that will perform a more efiicient sanding and polishing operation than has heretofore been accomplished.

Another object of this invention is to provide means within a belt sander and polisher for sanding and polish ing with a single pressure blade assembly so constructed as to apply a pressure sufficient for cutting purposes and also adjustable to apply a lighter pressure for polishing purposes, all in one assembly.

A further object of this invention is to provide a sanding and polishing pressure blade that will apply working pressure in concentrated unit areas to the sanding belt so positioned as to wear the sanding belt evenly throughout its major area.

Other objects and advantages will become apparent in the following specification when considered in the light of the attached drawings, in which:

Figure 1 is a plan View of a sanding and polishing machine incorporating the invention.

Figure 2 is an enlarged vertical sectional view, taken on the line 22 of Figure 1, looking in the direction indicated, with parts broken away for convenience of illustration.

Figure 3 is an enlarged fragmentary vertical crosssection taken on the line 3 3 of Figure 1, looking in the direction indicated.

Figure 4 is an enlarged fragmentary sectional view taken on the line 44 of Figure 3, looking in the direction indicated.

Figure 5 is a fragmentary enlarged detail sectional view similar to Figure 4.

Figure 6 is a bottom plan view of the cutting and polishing blade, parts broken away for convenience of illustration.

Figure 7 is an enlarged fragmentary sectional View taken on the line 77 of Figure 3, looking in the direction indicated.

Figure 8 is a fragmentary bottom plan view of a modified pressure blade structure partly broken away.

Figure 9 is an enlarged fragmentary sectional view,

taken on the line 9-9 of Figure 8, looking in the direction indicated.

Figure 10 is a fragmentary bottom plan View of another modified pressure blade structure.

Figure 11 is an enlarged fragmentary sectional view, taken on the line 11-11 of Figure 10, looking in the direction indicated.

JFigure 12 is a transverse cross-sectional view taken substantially along the line 12-12 of Figure 2, looking in the direction indicated.

Referring now to the drawings in detail wherein like reference characters indicate like parts throughout the several figures, the reference character M indicates gen- 2,803,927 Patented Aug. 27, 1957 erally a conventional type of sanding and polishing machine including supporting legs 10connected together at their upper ends by a cross beam 11 and by a beam 12 at their lower ends, and other associated framework elements (not shown).

An electric driving motor 13 is mounted on a bracket 14 carried by the machine M. The motor 13 carries a driving pulley 15 thereon about which a sanding belt 16 is trained. The opposite end of the belt 16 is trained about an idler pulley 17 journalled to the frame of the machine M in the usual manner.

A work supporting table T is movably mounted upon carriage tracks 18 on trunnion wheels 19 and supports the work P being sanded and polished. All of the above mechanism is conventional in sanding, cutting and polish-. ing machines.

The machine M has a pressure blade assembly A forming part thereof and including a basic or supporting bar 20. The bar 2th is pivotally supported at 20', referring to Figures 1 and 3, to a bracket 21 forming part of the cross beam 11 of the main frame of the machine M. The bar 20 is further supported on its ends by supporting brackets 22 through adjustable hanger bolts 23 carried thereby. The object of the adjustable hanger bolts 23 is to be able to level the bar 20 about the pivot 21 of the supporting bracket 21 and in relation to the mate rial being cut or polished.

Parallelly mounted to the underside of the supporting bar 20 is a second supporting bar 24. The bar 24 is connected to the bar 20 by links 25. The links 25 support the bar 24 in a parallel relation to the bar 20 and their adjusted position determines the relative height of a cutting and polishing pressure blade 26.

Referring particularly to Figures 1 and 2, a lever 27 is pivotally connected to the bar 20 at 28, with its lower end pivotally connected to the bar 24 at 29, and its upper end pivotally connected to a link 30 at 31. The link 30 connects pivotally to a crank 32, which is keyed to a shaft 33. The shaft 33 is journalled within a bearing 34 carried by the cross member 11 of the main frame.

An operating lever 35 is fixedly connected to the opposite end of the shaft 28 by a swivel connection 36 and rotates the shaft 33 as desired, thus operating the crank 34 and pivoting the lever 27 about its connection 28, moving the bar 24 longitudinally of the bar 20, causing the links 25 to raise and lower the bar 24 in reference to the supporting bar 20.

The pressure blade 26 of the pressure blade assembly A is connected to the floating supporting bar 24 by hanger bolts 37 having bases 38 formed thereon at their lower ends. The upper ends of the bolts 37 pass through openings 39 formed within the hanger bar 24 and are supported therein by lock nuts 40.

The bases 38 are mounted on the blade 26 by bolts 42 passing therethrough. Movement of the pressure blade 26 is substantially prevented by a connecting rod 25, which is pivotally connected to the supporting bar 24 at 25" and to the blade 26 at 25", permitting a very slight movement between the supporting bar 24 and the pressure blade 26.

The pressure blade 26 is formed of relatively thin fiat material flexible throughout its length and is supported by the bases 38 at spaced intervals. An even downward pressure on the blade 26 is accomplished by resilient rubber blocks 44 mounted between the supporting bar 24 and the upper surface of the blade 26.

The structure of the pressure plate 26, referring particularly to Figures 4, 5 and 6, includes strips 45 of relatively solid material secured to the bottom of the blade 26 at laterally spaced intervals and extending the full length of the blade 26. Disposed between and adjacent to the strips 45 are strips 4,6.of resilient material likewise extending the entire length of the blade 26.

It will be noted in Figure 6 that the end 47 of the blade 26 is wider than the end 43 and that the strips of material 45 and 46 widen towards the end 47. The object of thisformation is to provide a concentrated pressure on a unit area of the belt 16, but converging these pressure areas over the width of the belt 16 to provide an even wearing of-the belt 1-6inits operation. The strips 45 and 46 can be diverged so as'to-more completely cover the sanding 'belt area-throughoutthe length of the pressure assembly A even using a single width blade 26.

While we have-illustrated theistrips 45'and 46 diverging from one another in a continuous taper or fiare, we would not wish to be limited to this design, as the main object of diverging these strips 45 and 46 is to provide a series of :narrow pressure strips -45 and 46 applying a high localized unit pressure to the sanding belt 16, especially during the cutting operation, throughout the working length of the pressureblade 26 and sanding belt 16, but at the same time providing a pressure againstthe sandingbelt 16 so as to wearthis belt 16 evenly throughout its width.

The pressure area strips 45 and 46 could 'be of any shape or design on the face of the blade 26 for the carrying out of the objects of this invention, as for instance, referring to Figures 8 and.9, 10 and 11. The resilient pressure areas in Figure 8 are indicated as circular resilient pads 46', while the solid pressure area of the blade I Referring to Figures 10 and 11,

26' is indicated by 45. resilient strips 46 are disposed between the solid strips 45". These strips run angularly and transversely of the pressure blade 26".

A belt contact pad 49 covers the face of the strips 45 and .46. This pad 49 is secured to the blade 26by clamping strips 49'. Filler or pad protector strips 50 extend throughout the length of the edge of the pressure blade 26. The strips 56 do not apply a pressure to the upper surface of the sanding belt 16 while operating, but they protect the pad 49 over its entire area and also maintain the resilient strips 46 in place. Retaining strips 56 may also be used along the edge of the resilient strips 46 in order to maintain them in their proper working position.

Referring to Figures 1, 2, 3, 5 and 12, a sheet of plywoodPis illustrated being supported upon the supporting table T of the machine. One edge of the plywood P engages the guide rollers 51. The rollers 51 guide the sheet of plywood P through the machine M. Hold down rollers 52 are provided for holding the sheet P down against the top of the table T. The rollers 52 are journalled on cross shafts 53 supported by brackets 54 carried by the cross beam 11.

The operation of this new and improved sanding,

polishing and pressure blade assembly A is as follows: The operator places a sheet of material, such as plywood P upon the table T and the table T is moved under the upper run of the sanding belt 16. The adjusting hanger bolts 23 are adjusted tolevel the pressure blade assembly A in regards to the surface of the sheet P to be cut and polished. It will remain in this adjusted position as long as the same kind of sheets P are being sanded or polished.

He then grasps the lever 35, swinging the same about its swivel 36 so that he is able to reach the lever 35 when the table T is in its starting position, and as he moves forward with the table T feeding the same under the sanding belt 16, the lever 35 will hinge about its swivel 36 so that he has control of the same in the following operation.

On pulling the lever 35 downwardly, the crank 32 is revolved with the shaft 33, pulling the link 30 and pivoting the lever 27 about its pivot 28. This forces the pressure blade assembly supporting bar 24 downwardly, including the pressure blade assembly A wherein the under surface the sanding'belt 16. This heavy pressurewill cut the high points of the upper surface of the sheet P being processed by causing the sanding'belt to act as a cutting "belt, due to this heavy unit pressure.

After the sheet has been cut to the desired amount, the pressure on the handle 35 is partially released wherein only the pressure exerted by the resilient strips 46 is being applied to the pad 49 and to the upper surface of the sanding belt 16. This permits a polishing action by the sanding belt 16.

The principle of the heavy unit pressure for cutting using the solid strips 45 bearing down on the upper run of the sanding belt 16, and the releasing of these solid strips 45 and applying the pressure to the belt 16 by the resilient strips 46 is the heart of this invention, providing varied results by the operation of one control lever 35 in the applying of pressure through one single pressure blade assembly A.

Another feature of this invention is the ability to apply pressure by relatively narrow pressure strips by arranging these strips as to allow the belt 16 to work more freely, but at the same time so arranging these strips so that relatively all of the belt 16 is being used in the cutting or sanding operation.

By providing the resilient pressure material 41 between the movable supporting bar 24 and the pressure plate 26, the pressure plate assembly A is caused to follow the contour of the material being sanded, as for instance a piece of warped material. If a definite solid pressure throughout the length of the pressure blade 26 were applied the sanding belt would be cutting through the veneer face of thepiece of material being sanded at some points, which would be undesirable.

Having thus described the preferred embodiments of the invention, it should be understood that numerous structural modifications and adaptations may be resorted to without departing from the scope of the appended claims.

What is claimed is:

1. A pressure applying assembly for the belts of sanding and polishing machines comprising a framework, means mounting said framework on said machine for movement toward and away from said belt, a pressure blade on said framework, a plurality of resilient pressure members secured to the bottom of said blade, a plurality of rigid pressure members carried by said blade between said resilient members, and a pad secured to said blade and extending beneath said resilient and said rigid pressure members.

2. A device as claimed in claim 1 wherein said pressure blade is mounted on said framework by a plurality of elongated bolts and is spaced from said framework by a plurality of resilient blocks.

3. A device as claimed in claim 1 whereinsaid resilient pressure members and said rigid pressure members extend longitudinally of said pressure blade and diverge outwardly from one end thereof toward the other.

4. A device as claimed in claim 1 wherein hand controlled means is provided for moving said framework with relation to said machine.

5. A device as claimed in claim 1 wherein means are provided on said machine for levelling said framework with respect to said machine.

No references cited. 

